Pumping apparatus



W. F. MAY-ER PUMPING APPARATUS Filed July 18, 1938 Jan. 16, 1940..

4 Sheets-Sheet 1 KK W,

Jan. 16; 1940. w MAYER 2,186,983

PUMPING APPARATUS Filed July 18, 1938 4 Sheets-Sheet 2 Jan. 1940. w. F. mm 6 983 PUMPING APPARATUS Filed July 18, 1938 4 Sheets-Sheet 4 r F I l i -F 'W i i I i i i i I Q I; 29' 15A Qj/ S 71 k I S 7 77 34 N 76 \wb whom Patented Jan. 16, 1940 PUMPING APPARATUS Waldemar F. Mayer, Los Angeles, Calif., assignor to Byron Jackson (30.,

Huntington Park, Calif.,

a corporation of Delaware Application July 18, 1938, Serial No. 219,802

7 Claims.

This invention relates generally to hydraulic piston pumps; and particularly to a duplex hydraulic piston pump intended to provide steady, pulseless discharge.

A broad object of the invention is to reduce the cost and improve the performance, particularly with respect to smoothness of operation and of fluid discharge, of duplex hydraulic piston pumps.

The invention is particularly useful in mud pumps for handling drilling mud in connection with deep well drilling by the rotary method. Pumps employed in this service are subjected to extremely severe operating conditions because of the large volumes and high pressures required,

and also because of the abrasive nature of the drilling mud. Direct-acting duplex steam pumps are widly used, but are not ideally suited to this service for several reasons. The replacement cost of worn parts is very high, in many instances amounting to as much as the initial cost of the pump while drilling a single well; the discharge is pulsating, causing destructive vibration of the drill pipe and connecting lines; and the steam 25 consumption is unduly high because of the necessity of utilizing the fullstroke of the pistons, with no cut-elf.

Another object of the invention is to provide a duplex pump which is capable of withstanding 30 the severe operating conditions set forth above, and which will deliver drilling mud in a steady, pulseless stream at a wide range of pressures and volumes. The efliciency is greatly increased by the provision of a hydraulic pump capable of being operated by motive liquid supplied by a highly efficient centrifugal pump, which in turn may be driven by any eflicient and economical prime mover such as a steam turbine, an electric motor,

or an internal combustion engine.

A still further object is to provide a duplex pump having a set'of long stroke pistons and a set of short stroke pistons, the latter operating during reversal of the stroke of the former to provide continuous, steady discharge.

Other objects and advantages will be apparent as the description proceeds, reference being had to the accompanying drawings, wherein:

Fig. 1 is a plan view of a pump constructed in accordance with this invention;

Fig. 2 is a side elevation thereof;

Fig. 3 is an end elevation;

Fig. 4 is an enlarged plan view of thecentral portion of the pump, with parts {broken away as indicated on line 44 of Fig. 5,'t'o illustrate the general arrangement of the valve mechanisms;

Fig. 5 is a transverse vertical section taken on line 55 of Figs. 4 and 6;

Fig. 6 is a central longitudinal vertical section taken on line 6--6 of Figs. 4 and '7;

Fig. '7 is a central transverse vertical section taken on line 1-1 of Figs. 4 and. 6; and

Fig. 8 is a longitudinal vertical section taken on line 88 of Figs. 4 and 7.

Referring to the drawings, the pump comprises generally a central body A in which are housed the motive liquid valves and the pump liquid suction and discharge valves, and to opposite sides of which are secured a pair of elongated cylinders B, B in axial alignment with each other. A pair of relatively short cylinders C, C are also formed in the central body A, in axial alignment with each other and disposed at right angles to thevcylinders B, B. n

The main cylindersB, B are of double-walled construction, comprising inner cylinders II', II and concentric outer shells I2, I2 defining therebetween annular channels I3, I3 communicating at their outer ends with the interiors of the inner cylinders I I, I I". At their inner ends the channels I3, I3 communicate respectively with chambers I4. I4 in the central body A. Each of these chambers has valved connection through suction and discharge valves with a common pump liquid suction header I1 and a common pump liquid discharge chamber I8, respectively. Thus, as shown in Fig. 5, suction valve I5 and discharge valve I Ii communicate chamber M with the suction header I1 and with the discharge chamber I8, respectively.

A pair of pistons 2|, 2| are secured to opposite ends of a piston rod 22 for reciprocation in unison in the cylinders II, I I, respectively, the piston rod extending through a partition 23 separating the inner ends of the cylinders. 0n admission of motive liquid under pressure alternately to the cylinders on the inner sides of the pistons, the latter are reciprocated to force pump liquid out of one cylinder ahead of the respective piston and to draw pump liquid into the other cylinder behind the piston. Spent motive liquid is forced out of the other cylinder ahead of its piston. The valve mechanism for controlling the admission and discharge of motive liquid will be described hereinafter.

Referring no shown most clearly in Fig. 7, each is provided with an inner liner 26, 26' spaced from the outerwall to form channels 21, 21 corresponding to channels I3, I3 of the long cylinders. The channels 21, 21' communicate respectively with chambers to the short cylinders C, C','

28 (Fig. 5) and 28' (Fig. 8), the former having valved connection with the suction header I! through suction valve 29 and with the discharge chamber |8 through discharge valve 30, similar valves (not shown) being provided for the chamber 28.

Pistons 34, 34 are reciprocable in unison in the cylinders C, being secured to opposite ends of a piston rod 35. As in the case of the long cylinders, motive liquid is admitted alternately to the cylinders C, C to reciprocate the pistons 34, 34' and draw pump liquid from the suction header l1 and force it under pressure into the discharge chamber I8. Valve mechanism is provided for controlling the admission of motive liquid to the cylinders.

The valve mechanisms for controlling the flow of motive liquid to and from the two pairs of cylinders will now be described. As stated hereinabove, the short stroke pistons 34, 34' are re-' ciprocat'ed only during the reversal period of the long stroke pistons, to provide continuous, steady discharge of pump liquid. To this end, each pair of cylinders is provided with a reversing valve which is actuated by the pistons of the other pair of cylinders as they approach the end of their stroke. As shown in Fig. 4, a pair of reversing valves, generally designated R and R, are housed within the upper portionof the central body A, being disposed at right angles to each other, the valve R being disposed parallel to the long, or main, cylinders B, B and the valve R being parallel to the short, or auxiliary, cylinders C, C.

Valve R comprises a pair of connected shuttle valves 4 I, 4| (Fig. 7) shiftable from a right-hand positon, as shown, wherein motive liquid is admitted from an inlet 42 to a port 43 leading to main cylinder II and spent motive liquid is exhausted from main cylinder I through port 44 to discharge chamber 45, to a left-hand position wherein motive liquid is admitted to cylinder through port 44 and spent motive liquid is ex-- hausted from cylinder through port 43 to the discharge chamber 45.

Valve R (Fig. 6) is identical with valve R, having a pair of shuttle valves 5| controlling the admission of motive liquid from inlet 42 alternately through ports 52, 52 to the auxiliary cylinders C, C. To opposite ends of valve R are secured valve rods 53, 53" having connection through levers 54, 54' with rocker shafts 55, 55', whereby on oscillation of the shafts the valve will be reciprocated. As shown in Fig. 5, the

rocker shafts are journaled in the central body on upright axes and extend downwardly therein to adjacent the cylinders II. On the lower ends of the shafts are actuating fingers 56, 56' which project into the cylinders in the paths of sleeves 51, 51' secured to the piston rod 22 adjacent the pistons 2|, 2|. As each piston approaches the inner end of its stroke a finger 56 or 56' is engaged by the respective sleeve 51 or 51 to rock the shafts 55, 55"and reverse the valve R.

Valve R is. similarly provided with valve rods 6|, 6|, levers 62, 62', rock shafts 63, 63', and

viewed in Fig. 6. Valve R (Fig. 7) which controls the main piston, is shifted to the right to admit motive liquid to cylinder B on the inner side of piston 2|, and to exhaust spent motive liquid from cylinder B. The auxiliary pistons 34, 34 are at rest at the right-hand ends of their cylinders, with motive liquid being applied to cylinder C due to the position of valve R to the left.

The actuating sleeve 51 associated with piston 2| is about to engage the actuating fingerSi, and when this occurs valve R will be shifted to the right to admit motive liquid to the left-hand auxiliary cylinder C. The auxiliary pistons will thus be moved to the left, and after travelling only a short distance the sleeve 65' will engage actuating finger 64, reversing the main valve R. The auxiliary pistons continue to travel to the left until piston 34 engages the cover plate at the outer end of the cylinder C, the piston speed of both sets of pistons being greatly reduced, however, during simultaneous movement. This is due to the fact that the volume of motive liquid remains constant, and is divided between the two cylinders. After the auxiliary pistons have come to rest the speed of the main pistons increases, inasmuch as they then receive the total displacement of the motive liquid pump. On approaching the left end of their stroke, the actuating sleeve 51 associated with main piston 2| engages actuating finger 56 to reverse the auxiliary valve R, and the operation is repeated.

While it is believed preferable to provide auxiliary pistons with a stroke only sufliciently long to take care of reversal of the main pistons, it will be appreciated that the relative lengths of the strokes may be any desired ratio.

By the provision of pistons actuated directly by motive liquid, many advantages are realized. The pressure differential across the pistons is very small, resulting in practically entire elimination of wear on the cylinder walls and pistons. The piston rods are always under tension, thus removing the limitation imposed on the stroke length when the rods are under compression. With at least one long stroke unit the frequency of reversals is reduced, effecting material savings in wear and tear on the valves, particularly the pump liquid suction and discharge valves. Other advantages will be apparent to those skilled in this art.

I claim:

1. Hydraulic pumping apparatus comprising, in combination: a pair of reciprocating piston pump units of the fluid pressure actuated type, common motive liquid inlet and outlet connections and pump liquid inlet and discharge connections to said units, valve means for controlling the flow of motive liquid to and from each of said units to actuate the same, the valve means associated with each unit being actuated in predetermined relation to the piston movement of the other unit whereby each unit pumps during the stroke-reversing period of the other unit to maintain continuous how of motive and pump liquids, the stroke of one of said units being relatively short in comparison to the stroke of said other unit and of minimum length sufllcient only to maintain continuous flow of liquid during instantaneous reversal oi the piston of the other unit whereby the idle time of said other unit is minimized.

2. Apparatus as defined in claim 1, in which the valve means associated with the short-stroke unit is actuated adjacent the end of the stroke of the long-stroke unit, and the valve means associated with the long-stroke unit is actuated adjacent the beginning of the stroke of the shortstroke unit.

3. Hydraulic pumping apparatus comprising a pair of aligned cylinders, a pair of interconnected pistons reciprocable in unison in said cylinders, a second pair of aligned cylinders disposed substantially at right angles to said first named cylinders,

interconnected pistons reciprocable in said second-namedcylinders, motive liquid inlet and outlet connections and pump liquid inlet and discharge connections to said cylinders, valve means disposed substantially parallel to each of said pairs of cylinders and operatively connected with the pistons thereof whereby each valve means is actuated in predetermined timed relationship to the movement of the pair of pistons parallel thereto, and motive liquid connections between each valve means and the cylinders disposed at right angles thereto.

4. A duplex hydraulic pump comprising'a central body, a pair of cylinders secured to opposite sides of said body in coaxial alignment, pistons reciprocable in said cylinders, a second pair of cylinders disposed on opposite sides of said central body in coaxial alignment and substantially at right angles to said first-named cylinders, pistons reciprocable in said second-named cylinders,

. motive liquid inlet and outlet connections and pump liquid inlet and discharge connections to said pump, a pair of motive liquid valve means in said central body, each of said valve means being disposed parallel to one of said pairs of cylinders and having operative connection therewith for actuating the valves in predetermined timed relationship to the movement of the pistons parallel thereto, and motive liquid connections from each valve means to the cylinders at right angles thereto.

5. Apparatus as defined in claim 3, in which one of said pairs of cylinders are relatively short in comparison to the length of said other pair.

6. Apparatus as defined in claim 4, in which said second-named pair of cylinders are relatively short and are disposed within said central body.

7. Apparatus as defined in claim 4, in which said motive liquid inlet and outlet connections and said pump liquid inlet and discharge con- F nections are formed in said central body.

WALDEMAR F. MAYER. 

